Default PDF viewer in Safari... removing Adobe Reader

Question

I recently installed Adobe Reader because I find it easier to mark-up documents than in Preview, and now it is the default viewer in Safari.  I have tried to change this, but the help I have found on the internet isn't working... there is no internet plug-in (that I can find) to delete, and the preferences in Reader have the "Display PDF in browser using" box grayed-out, so I can't check that either.  Any advice?
Also, if you know of a better program for reading PDFs (my main problem with mark-ups on preview is that it doesn't isolate individual columns, so when highlighting, it highlights all the way across the page, as opposed to individual columns) then please share!
Thanks!

Answer 1

Here is the link with instructions from Adobe.
http://helpx.adobe.com/acrobat/using/display-pdf-browser-acrobat-xi.html
Go to the section called "Disable AdobePDFViewer plug-in" and follow the instructions.
You must have root user privileges to change the Safari plug-ins. To display PDFs using the Safari PDF viewer, you must disable the Adobe PDF Viewer.
Quit Safari.
Log in as the root user. The root user privileges aren't enabled by default because the root user can change system files. For more information and instructions, see one of the following Apple documents: Enabling and using the "root" user in Mac OS X or OS X Mountain Lion: Enable and disable the root user.
Choose Go > Go To Folder.
Type /Library in the Go To The Folder field, and click Go.
Create a new folder in the Library folder, and name it Internet Plug-ins Disabled.
Open the Internet Plug-ins folder, and move both the AdobePDFViewer.plugin and the AdobePDFViewerNPAPI.plugin into the new Internet Plug-ins Disabled folder.
Note:
If both AdobePDFViewer plug-ins are still in the Internet Plug-ins folder, drag them now to the trash. You may be asked for your name and password.